A cascade acetylene carbonylation synthesis reaction method and system

Abstract

The present invention discloses a cascade acetylene carbonylation synthesis reaction method and system, belonging to the field of chemical production technology. The method of the present invention adopts a cascade reaction, including: S1. primary reaction: in the first-stage reaction container, acetylene, carbon monoxide and water react in a solvent through the catalysis of a catalyst system; S2. secondary reaction: the reaction system after the primary reaction is sent to the second-stage reaction container for continued reaction to generate a crude succinic acid product. The reaction system disclosed in the present invention includes a primary reactor, a secondary reactor, and a crystallization solid-liquid separation unit connected in sequence; the primary reactor is connected to a desalted water conveying line and an acetylene / carbon monoxide raw gas conveying line, and the crystallization solid-liquid separation unit is connected to a crude succinic acid product conveying line and a separation liquid output line. The present invention adopts a two-stage cascade reaction, which solves the problems of many side reactions and short catalyst life in the acetylene carbonylation reaction, realizes the complete recycling of the reaction liquid, and the long-term continuous operation of the production device.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and in particular relates to a cascade acetylene carbonylation synthesis reaction method and system. Background Art

[0002] Globally, the main constraint on the development of the succinic acid industry is the expensive production cost. As countries around the world attach great importance to the living environment, the consumption demand for succinic acid in the environmental protection industry will become higher and higher. In particular, the application and promotion of PBS industrialization technology worldwide and the huge market demand for degradable plastics will make the succinic acid market have a better development prospect. At present, the mainstream technical routes at home and abroad are biological fermentation, maleic anhydride electrolytic hydrogenation and maleic anhydride catalytic hydrogenation. Among them, the upstream of maleic anhydride method comes from petroleum, and the raw material of biological fermentation method comes from starch, which is not suitable for my country's resource endowment. The development of natural gas and coal chemical industry is a strategic demand of the country. At present, most natural gas and coal chemical products are in a state of overcapacity, which has led to restrictions on industrial development. The development and utilization of downstream products has become the key to industrial development. Using natural gas or coal to produce acetylene, and then using acetylene and carbon monoxide as raw materials to synthesize succinic acid can not only greatly reduce the production cost of succinic acid and promote the application of PBS, but also has important significance for promoting the healthy development of natural gas and coal chemical industry.

[0003] Patent CN107739309A discloses a palladium-catalyzed dicarbonylation preparation method for acetylene, which adopts homogeneous catalytic reaction, and the palladium compound is completely dissolved in the reaction system. However, the homogeneous catalytic system has a high catalytic activity, so that in addition to the main reaction of acetylene dicarbonylation to generate C4 target products (the target products are succinic acid, butenedioic acid and its anhydride), there are several side reactions that will inevitably occur: ① acetylene undergoes a single carbonylation reaction to generate acrylic acid or propionic acid; ② generates high molecular weight hydrocarbons; ③ when the reaction conditions are not well controlled, the catalyst activity may also decrease. The above three situations will all lead to a decrease in the total selectivity of the target C4 product. In order to maintain the normal reaction, it is necessary to continuously separate the by-products from the reaction system by methods such as distillation, which greatly increases the production cost. At the same time, the solid by-products are difficult to separate from the product mixture, which seriously affects the product purity and even causes the catalyst activity to decrease.

[0004] In the traditional single-stage reaction process, a bubbling kettle reactor is used as the space for acetylene carbonylation reaction. Acetylene and carbon monoxide are mixed and introduced into the reactor. Bubbling reaction occurs in the liquid solvent. The reactants leave the reactor together with the solvent. After the solid product is separated by crystallization, part of the reaction liquid returns to the reactor, and part of it is separated by distillation to separate the gas phase by-products so that the by-products do not accumulate too much. There are the following disadvantages in using this method to recover the catalyst:

[0005] (1) Distillation separation of by-products leads to increased energy consumption.

[0006] (2) During the distillation process, heating causes the activity of the catalyst dissolved in the reaction liquid to decrease. The mother liquor in the tower bottom needs to go through a catalyst recovery process to separate and prepare the catalyst and return it to the reaction system for use. This process is long and costly.

[0007] (3) The solid by-products are mixed with the C4 products which are also solid, making it difficult to separate them effectively, resulting in reduced purity of the products.

[0008] (4) Side reactions will occupy the active sites of the catalyst, causing the catalyst activity to slowly decrease. It is necessary to replace all reaction solvents every few weeks and restart the plant, which is very detrimental to the continuous production of the plant.

[0009] The above problems make it difficult to realize the industrialization of acetylene carbonylation reaction to produce succinic acid. How to effectively inhibit the occurrence of side reactions, improve reaction selectivity, reduce production costs, and promote the industrialization of homogeneous catalytic acetylene carbonylation reaction to produce succinic acid has become a problem that technicians in this field need to solve urgently. Summary of the invention

[0010] One of the purposes of the present invention is to provide a cascade acetylene carbonylation synthesis reaction system to solve the problems of many side reactions, short catalyst life and low product purity in the prior art of acetylene dicarbonylation.

[0011] The second object of the present invention is to provide a cascade acetylene carbonylation synthesis reaction method, which is carried out using the above reaction system.

[0012] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0013] On the one hand, the present invention discloses a cascade acetylene carbonylation synthesis reaction method, which adopts a cascade reaction and comprises the following steps:

[0014] S1. Primary reaction: In the first stage reaction vessel, acetylene, carbon monoxide and water react in a solvent catalyzed by a catalyst system;

[0015] S2. Secondary reaction: The reaction system after the primary reaction is fed into a second-stage reaction vessel, where the reaction continues to occur to generate a crude succinic acid product;

[0016] Preferably, the first-stage reaction vessel is a single unit or multiple units are connected in parallel;

[0017] Preferably, the second-stage reaction vessel is a single vessel or multiple vessels are connected in parallel.

[0018] In some embodiments of the present invention, the temperature and reaction time of the secondary reaction are greater than those of the primary reaction;

[0019] Preferably, the temperature of the primary reaction is 20-70° C., and the reaction residence time is 1-30 min; the temperature of the secondary reaction is 40-80° C., and the reaction residence time is 30-90 min.

[0020] In some embodiments of the present invention, the molar ratio of acetylene, carbon monoxide and water in the primary reaction is 1:1.8-5:1-10.

[0021] In some embodiments of the present invention, in step S2, an excess amount of carbon monoxide is introduced into the reaction system.

[0022] In some embodiments of the present invention, the method further comprises a separation step: S3. Crystallization separation: cooling, crystallizing, and solid-liquid separation are performed on the reaction system after the secondary reaction, and the solid obtained by separation is a crude succinic acid product;

[0023] Preferably, the separated liquid after liquid-solid separation is circulated back to S1 to participate in the reaction again;

[0024] More preferably, the separated liquid after liquid-solid separation is saturated with carbon monoxide and then circulated back to the primary reactor.

[0025] On the other hand, the present invention discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor, a secondary reactor, and a crystallization solid-liquid separation unit connected in sequence;

[0026] The primary reactor is connected to the desalted water delivery line and the acetylene / carbon monoxide raw gas delivery line.

[0027] The crystallization solid-liquid separation unit is connected to a crude succinic acid product conveying line and a separation liquid output line.

[0028] In some embodiments of the present invention, the primary reactor is a tubular reactor, a falling film reactor or a bubbling tank reactor, and the secondary reactor is a bubbling tank reactor or a tower reactor.

[0029] The present invention adopts a two-stage reactor, and through a two-stage cascade reaction, the side reaction of the acetylene carbonylation reaction can be effectively reduced and the reaction selectivity can be improved.

[0030] The crystallization solid-liquid separation unit in the present invention is a prior art, which is used to cool, crystallize, and perform liquid-solid separation on the system after the reaction.

[0031] In some embodiments of the present invention, the secondary reactor is connected to a carbon monoxide feed gas input pipe I. In this arrangement, carbon monoxide can be introduced during the secondary reaction, which can further suppress the side reactions of the acetylene carbonylation reaction and improve the reaction selectivity.

[0032] In some embodiments of the present invention, the system further comprises a cooler, and the tail gas outlets of the primary reactor and the secondary reactor are respectively connected to the cooler via pipelines; the liquid outlet of the cooler is connected to the secondary reactor via a pipeline; the gas outlet of the cooler is connected to a non-condensable gas delivery line;

[0033] Preferably, the non-condensable gas delivery line is connected to the circulating gas compressor, the circulating gas compressor is connected to the purge gas delivery line and the circulating gas delivery line, and the circulating gas delivery line is connected to the secondary reactor;

[0034] Preferably, the carbon monoxide raw gas input pipe I is connected to the non-condensable gas delivery line and connected to the secondary reactor via the circulating gas delivery line.

[0035] In some embodiments of the present invention, the separation liquid output line is connected to the primary reactor;

[0036] Preferably, an air dissolving pump is provided on the separation liquid output line, and the air dissolving pump is connected to the carbon monoxide raw material delivery line II.

[0037] In the present invention, the separation liquid output line is connected to the primary reactor; the separation liquid obtained by cooling crystallization and liquid-solid separation is returned to the primary reactor, thereby realizing the recycling of materials. An air dissolving pump connected to the carbon monoxide raw material conveying line II is arranged on the separation liquid output line, and carbon monoxide is dissolved in the separation liquid and then returned to the primary reactor to participate in the reaction, thereby effectively improving the selectivity of the reaction.

[0038] In some embodiments of the present invention, a circulating cooler is provided outside the secondary reactor. The carbonylation reaction is an exothermic reaction, and the reaction temperature is controlled by cooling the circulating cooler.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The invention has scientific design, ingenious conception and simple method, and effectively solves the side reaction problem of acetylene carbonylation reaction.

[0041] The present invention creatively adopts a two-stage series reaction, and solves the problems of many side reactions and short catalyst life in acetylene carbonylation reaction through the two-stage reaction. The reaction liquid after liquid-solid separation does not need to be distilled to separate by-products, and can be directly returned to the reactor, thereby achieving complete recycling of the reaction liquid and long-term continuous operation of the production device.

[0042] In the method of the present invention, the primary reactor and the secondary reactor have different mass transfer characteristics and reaction parameters. The primary reactor has a shorter reaction residence time, a lower reaction temperature and a lower carbon-to-yne ratio, and the secondary reactor has a longer reaction residence time, a higher reaction temperature and a higher carbon-to-yne ratio, thereby achieving effective suppression of side reactions, changing the process mode of recycling the reaction liquid, and improving the stability of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Attached Figure 1 It is a schematic structural diagram of the reaction system of the present invention.

[0044] The names corresponding to the reference numerals are:

[0045] 1-primary reactor, 2-secondary reactor, 3-crystallization solid-liquid separation unit, 4-dissolved air pump, 5-cooler, 6-circulating air compressor, 7-circulating cooler;

[0046] 101- desalted water conveying line, 102- acetylene / carbon monoxide raw gas conveying line, 103- succinic acid crude product conveying line, 104- separated liquid output line, 105- carbon monoxide raw gas input pipe I, 106- non-condensable gas delivery line, 107- purge gas delivery line, 108- circulating gas conveying line, 109- carbon monoxide raw material conveying line II. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0048] Embodiments 1 to 5 disclose a cascade acetylene carbonylation synthesis reaction system of the present invention.

[0049] Example 1

[0050] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, and a crystallization solid-liquid separation unit 3 connected in sequence;

[0051] The primary reactor is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102.

[0052] The crystallization solid-liquid separation unit 3 is connected to a crude succinic acid product conveying line 103 and a separation liquid output line 104 .

[0053] Example 2

[0054] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, and a crystallization solid-liquid separation unit 3 connected in sequence;

[0055] The primary reactor is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102.

[0056] The crystallization solid-liquid separation unit 3 is connected to a crude succinic acid product conveying line 103 and a separation liquid output line 104 .

[0057] The primary reactor 1 is a tubular reactor, a falling film reactor or a bubbling kettle reactor, and the secondary reactor 2 is a bubbling kettle reactor or a tower reactor.

[0058] This Example 2 provides a more preferred technical solution for the primary reactor and the secondary reactor based on Example 1. Specifically, the primary reactor 1 is a tubular reactor or a falling film reactor or a bubbling kettle reactor, and the secondary reactor 2 is a bubbling kettle reactor or a tower reactor.

[0059] Example 3

[0060] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, and a crystallization solid-liquid separation unit 3 connected in sequence;

[0061] The primary reactor is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102.

[0062] The crystallization solid-liquid separation unit 3 is connected to a crude succinic acid product conveying line 103 and a separation liquid output line 104 .

[0063] The primary reactor 1 is a tubular reactor, a falling film reactor or a bubbling kettle reactor, and the secondary reactor 2 is a bubbling kettle reactor or a tower reactor.

[0064] The secondary reactor 2 is connected to a carbon monoxide raw gas input pipe I105.

[0065] This embodiment 3 provides a more preferred technical solution based on embodiment 2. Specifically, the secondary reactor 2 is connected to a carbon monoxide raw gas input pipe I105.

[0066] Example 4

[0067] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, a crystallization solid-liquid separation unit 3 and a cooler 5 connected in sequence;

[0068] The primary reactor is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102 , and the crystallization solid-liquid separation unit 3 is connected to a succinic acid crude product delivery line 103 and a separation liquid output line 104 .

[0069] The primary reactor 1 is a tubular reactor, a falling film reactor or a bubbling kettle reactor, and the secondary reactor 2 is a bubbling kettle reactor or a tower reactor.

[0070] The secondary reactor 2 is connected to a carbon monoxide raw gas input pipe I105.

[0071] The tail gas outlet of the primary reactor 1 and the tail gas outlet of the secondary reactor 2 are respectively connected to the cooler 5 via pipelines; the liquid outlet of the cooler 5 is connected to the secondary reactor 2 via a pipeline; the gas outlet of the cooler 5 is connected to the non-condensable gas delivery line 106.

[0072] The non-condensable gas delivery line 106 is connected to the circulating gas compressor 6, and the circulating gas compressor 6 is connected to the purge gas delivery line 107 and the circulating gas delivery line 108, and the circulating gas delivery line 108 is connected to the secondary reactor 2;

[0073] The carbon monoxide raw gas input pipe I105 is connected to the non-condensable gas delivery line 106, and is connected to the secondary reactor 2 through the circulating gas delivery line 108.

[0074] This embodiment 4 provides a more preferred technical solution based on embodiment 3, specifically: the system also includes a cooler 5, the tail gas outlet of the first reactor 1 and the tail gas outlet of the second reactor 2 are respectively connected to the cooler 5 via pipelines; the liquid outlet of the cooler 5 is connected to the second reactor 2 via a pipeline; the gas outlet of the cooler 5 is connected to a non-condensable gas delivery line 106; the non-condensable gas delivery line 106 is connected to the circulating gas compressor 6, the circulating gas compressor 6 is connected to a purge gas delivery line 107 and a circulating gas delivery line 108, and the circulating gas delivery line 108 is connected to the second reactor 2; the carbon monoxide raw gas input pipe I105 is connected to the non-condensable gas delivery line 106, and is connected to the second reactor 2 via the circulating gas delivery line 108.

[0075] Example 5

[0076] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, a crystallization solid-liquid separation unit 3 and a cooler 5 connected in sequence;

[0077] The primary reactor is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102.

[0078] The crystallization solid-liquid separation unit 3 is connected to a crude succinic acid product conveying line 103 and a separation liquid output line 104 .

[0079] The primary reactor 1 is a tubular reactor, a falling film reactor or a bubbling kettle reactor, and the secondary reactor 2 is a bubbling kettle reactor or a tower reactor.

[0080] The secondary reactor 2 is connected to a carbon monoxide raw gas input pipe I105.

[0081] The tail gas outlet of the primary reactor 1 and the tail gas outlet of the secondary reactor 2 are respectively connected to the cooler 5 via pipelines; the liquid outlet of the cooler 5 is connected to the secondary reactor 2 via a pipeline; the gas outlet of the cooler 5 is connected to the non-condensable gas delivery line 106.

[0082] The non-condensable gas delivery line 106 is connected to the circulating gas compressor 6, and the circulating gas compressor 6 is connected to the purge gas delivery line 107 and the circulating gas delivery line 108, and the circulating gas delivery line 108 is connected to the secondary reactor 2;

[0083] The carbon monoxide raw gas input pipe I105 is connected to the non-condensable gas delivery line 106, and is connected to the secondary reactor 2 through the circulating gas delivery line 108.

[0084] The separation liquid output line 104 is connected to the primary reactor 1; the separation liquid output line 104 is provided with an air dissolving pump 4, and the air dissolving pump 4 is connected to the carbon monoxide raw material conveying line II109.

[0085] A circulating cooler 7 is arranged outside the secondary reactor 2 .

[0086] This embodiment 5 provides a more preferred technical solution based on the embodiment 4, specifically: the separation liquid output line 104 is connected to the primary reactor 1; the separation liquid output line 104 is provided with a dissolved air pump 4, and the dissolved air pump 4 is connected to the carbon monoxide raw material delivery line II109. A circulating cooler 7 is provided outside the secondary reactor 2.

[0087] Example 6

[0088] As attached Figure 1 As shown, this embodiment discloses a cascade acetylene carbonylation synthesis reaction system, comprising a primary reactor 1, a secondary reactor 2, and a crystallization solid-liquid separation unit 3 connected in sequence;

[0089] The primary reactor 1 is connected to a desalted water delivery line 101 and an acetylene / carbon monoxide feed gas delivery line 102.

[0090] The crystallization solid-liquid separation unit 3 is connected to a crude succinic acid product conveying line 103 and a separation liquid output line 104 .

[0091] The number of the primary reactors 1 is greater than or equal to 1. When the number of the primary reactors is greater than 1, the primary reactors are distributed in parallel;

[0092] The number of the secondary reactors 2 is greater than or equal to 1. When the number of the secondary reactors is greater than 1, the secondary reactors are distributed in parallel.

[0093] This embodiment 6 provides a more preferred technical solution for the primary reactor and the secondary reactor based on the embodiment 1. That is: the number of primary reactors 1 is greater than or equal to 1, and when the number of primary reactors is greater than 1, the primary reactors are distributed in parallel; the number of secondary reactors 2 is greater than or equal to 1, and when the number of secondary reactors is greater than 1, the secondary reactors are distributed in parallel. Embodiments 7 to 10 disclose the synthesis reaction method of the present invention.

[0094] Example 7

[0095] This embodiment 7 discloses a cascade acetylene carbonylation synthesis reaction method, which is carried out using the system of embodiment 2. The specific steps are as follows:

[0096] S1. Desalted water is fed into the primary reactor via the desalted water delivery line, and carbon monoxide and acetylene raw gas are fed into the primary reactor via the acetylene / carbon monoxide raw gas delivery line; carbon monoxide, acetylene and desalted water are reacted in acetonitrile containing a catalyst system at 20°C for 30 minutes, and then the reaction system is fed into the secondary reactor; wherein the molar ratio of acetylene, carbon monoxide and water is 1:4:1;

[0097] S2. After the reaction system was kept in the secondary reactor at 40°C for 90 minutes, the reaction system was sent to the crystallization solid-liquid separation unit;

[0098] S3. In the crystallization solid-liquid separation unit, the solid is separated by cooling and crystallization, and the solid is separated as a crude succinic acid product;

[0099] The primary reactor in this embodiment is a tubular reactor, and the secondary reactor is a bubbling tank reactor.

[0100] By using the method of this embodiment, the purity of the crude succinic acid product obtained is 75% to 80%.

[0101] The catalyst life is increased by 50% compared with the traditional single-stage reaction.

[0102] Example 8

[0103] This Example 8 discloses a cascade acetylene carbonylation synthesis reaction method, which is carried out using the system of Example 2. The specific steps are as follows:

[0104] S1. Desalted water is fed into the primary reactor via the desalted water delivery line, and carbon monoxide and acetylene raw gas are fed into the primary reactor via the acetylene / carbon monoxide raw gas delivery line; carbon monoxide, acetylene and desalted water are reacted in acetonitrile containing a catalyst system at 70°C for 1 minute, and then the reaction system is fed into the secondary reactor; wherein the molar ratio of acetylene, carbon monoxide and water is 1:4:1;

[0105] S2. After the reaction system was allowed to react at 80°C in the secondary reactor for 30 minutes, the reaction system was sent to the crystallization solid-liquid separation unit;

[0106] S3. In the crystallization solid-liquid separation unit, the solid obtained by cooling crystallization and liquid-solid separation is a crude succinic acid product; the purity of the crude succinic acid product is 80% to 85%.

[0107] The primary reactor in this embodiment is a tubular reactor, and the secondary reactor is a bubbling tank reactor.

[0108] By adopting the method of this embodiment, the life of the catalyst is increased by 50% compared with the conventional single-stage reaction.

[0109] Example 9

[0110] This Example 9 discloses a cascade acetylene carbonylation synthesis reaction method, which is carried out using the system of Example 3. The specific steps are as follows:

[0111] S1. Desalted water is fed into the primary reactor via the desalted water delivery line, and carbon monoxide and acetylene raw gas are fed into the primary reactor via the acetylene / carbon monoxide raw gas delivery line; carbon monoxide, acetylene and desalted water are reacted in acetonitrile containing a catalyst system at 70°C for 1 minute, and then the reaction system is fed into the secondary reactor; wherein the molar ratio of acetylene, carbon monoxide and water is 1:4:1.

[0112] S2. Excessive carbon monoxide gas is introduced into the secondary reactor, and the reaction system sent from the primary reactor and the introduced carbon monoxide gas are reacted at 80 ° C in the secondary reactor for 30 minutes, and then the reaction system is sent to the crystallization solid-liquid separation unit;

[0113] S3. In the crystallization solid-liquid separation unit, the solid is separated by cooling and crystallization, and the solid is separated as a crude succinic acid product;

[0114] The primary reactor in this embodiment is a tubular reactor, and the secondary reactor is a bubbling tank reactor.

[0115] By using the method of this embodiment, the purity of the crude succinic acid product obtained is 80% to 85%.

[0116] By adopting the method of this embodiment, the life of the catalyst is increased by 50% compared with the conventional single-stage reaction.

[0117] Example 10

[0118] This embodiment 10 discloses a cascade acetylene carbonylation synthesis reaction method, which is carried out using the system of embodiment 5. The specific steps are as follows:

[0119] S1. Desalted water is fed into the primary reactor via the desalted water delivery line, and carbon monoxide and acetylene raw gas are fed into the primary reactor via the acetylene / carbon monoxide raw gas delivery line; carbon monoxide, acetylene and desalted water are reacted in acetonitrile containing a catalyst system at 50°C for 20 minutes, and then the reaction system is fed into the secondary reactor; wherein the molar ratio of acetylene, carbon monoxide and water is 1:4:1;

[0120] S2. Excessive carbon monoxide gas is introduced into the secondary reactor, and the reaction system sent from the primary reactor and the introduced carbon monoxide gas are reacted at 80 ° C in the secondary reactor for 30 minutes, and then the reaction system is sent to the crystallization solid-liquid separation unit;

[0121] The tail gas from the primary reactor and the secondary reactor enters the cooler, and the liquid obtained after cooling is sent to the secondary reactor to participate in the reaction. The non-condensable gas and carbon monoxide gas are sent to the secondary reactor together after being pressurized to participate in the reaction.

[0122] S3. In the crystallization solid-liquid separation unit, the solid obtained by cooling and crystallization and liquid-solid separation is a crude succinic acid product; the separated liquid obtained by separation is saturated with carbon monoxide and then sent to the primary reactor for circulation to participate in the reaction.

[0123] The primary reactor in this embodiment is a falling film reactor, and the secondary reactor is a tower reactor.

[0124] By adopting the method of this embodiment, the purity of the obtained crude succinic acid product is 80% to 85%.

[0125] By adopting the method of this embodiment, the life of the catalyst is increased by 50% compared with the conventional single-stage reaction.

[0126] The crystallization solid-liquid separation operation in the embodiment of the present invention is a prior art and can be performed according to the method disclosed in patent CN115518655 A.

[0127] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solution of the present invention, but not to limit it, and certainly not to limit the patent scope of the present invention. Any changes or modifications that have no substantial significance on the main design concept and spirit of the present invention, which solve technical problems consistent with the present invention, should be included in the protection scope of the present invention; in addition, the direct or indirect application of the technical solution of the present invention in other related technical fields should also be included in the patent protection scope of the present invention.

Claims

1. A cascade acetylene carbonylation synthesis reaction method, characterized in that: The cascade reaction is adopted, including the following steps: S1. Primary reaction: In the first stage reaction vessel, acetylene, carbon monoxide and water react in a solvent catalyzed by a catalyst system; S2. Secondary reaction: The reaction system after the primary reaction is fed into a second-stage reaction vessel, where the reaction continues to occur to generate a crude succinic acid product; Preferably, the first-stage reaction vessel is a single unit or multiple units are connected in parallel; Preferably, the second-stage reaction vessel is a single vessel or multiple vessels are connected in parallel.

2. A cascade acetylene carbonylation synthesis reaction method according to claim 1, characterized in that: The temperature and reaction time of the secondary reaction are greater than those of the primary reaction; Preferably, the temperature of the primary reaction is 20-70° C., and the reaction residence time is 1-30 min; the temperature of the secondary reaction is 40-80° C., and the reaction residence time is 30-90 min.

3. A cascade acetylene carbonylation synthesis reaction method according to claim 1 or 2, characterized in that: In step S2, an excess amount of carbon monoxide is introduced into the reaction system.

4. A cascade acetylene carbonylation synthesis reaction method according to claim 1 or 2, characterized in that: The step of separation is also included: S3. Crystallization separation: cooling, crystallizing, and solid-liquid separation are performed on the reaction system after the secondary reaction, and the solid obtained by separation is a crude succinic acid product; Preferably, the separated liquid after liquid-solid separation is circulated back to S1 to participate in the reaction again; More preferably, the separated liquid after liquid-solid separation is saturated with carbon monoxide and then circulated back to the primary reactor.

5. A cascade acetylene carbonylation synthesis reaction system for use in the method according to any one of claims 1 to 4, characterized in that: It comprises a primary reactor (1), a secondary reactor (2), and a crystallization solid-liquid separation unit (3) which are connected in sequence; The primary reactor is connected to a desalted water delivery line (101) and an acetylene / carbon monoxide feed gas delivery line (102); The crystallization solid-liquid separation unit (3) is connected to a crude succinic acid product delivery line (103) and a separation liquid output line (104).

6. A cascade acetylene carbonylation synthesis reaction system according to claim 5, characterized in that: The primary reactor (1) is a tubular reactor, a falling film reactor or a bubbling kettle reactor, and the secondary reactor (2) is a bubbling kettle reactor or a tower reactor.

7. The cascade acetylene carbonylation synthesis reaction system according to claim 5, characterized in that: The secondary reactor (2) is connected to a carbon monoxide raw gas input pipe I (105).

8. A cascade acetylene carbonylation synthesis reaction system according to any one of claims 5 to 7, characterized in that: It also includes a cooler (5), and the tail gas outlet of the primary reactor (1) and the tail gas outlet of the secondary reactor (2) are respectively connected to the cooler (5) through pipelines; The liquid outlet of the cooler (5) is connected to the secondary reactor (2) via a pipeline; the gas outlet of the cooler (5) is connected to a non-condensable gas delivery line (106); Preferably, the non-condensable gas delivery line (106) is connected to the circulating gas compressor (6), the circulating gas compressor (6) is connected to a purge gas delivery line (107) and a circulating gas delivery line (108), and the circulating gas delivery line (108) is connected to the secondary reactor (2); Preferably, the carbon monoxide raw gas input pipe I (105) is connected to the non-condensable gas delivery line (106), and is connected to the secondary reactor (2) via the circulating gas delivery line (108).

9. A cascade acetylene carbonylation synthesis reaction system according to any one of claims 5 to 7, characterized in that: The separation liquid output line (104) is connected to the primary reactor (1); Preferably, an air dissolving pump (4) is provided on the separation liquid output line (104), and the air dissolving pump (4) is connected to a carbon monoxide raw material delivery line II (109).

10. A cascade acetylene carbonylation synthesis reaction system according to any one of claims 5 to 7, characterized in that: A circulating cooler (7) is arranged outside the secondary reactor (2).

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